Data centers contain large number of servers and other assets. Current systems that attempt to autonomously or remotely determine asset location, often offer incomplete or unreliable data. As a result of this situation, inventory management and auditing of data center facilities (often sites that contain hundreds of racks and thousands of individual computing, communication and other miscellaneous assets) may need to be performed or verified manually. A further complication of inventory information is that it is often superseded by onsite alterations or undocumented changes. Hence it can be difficult for operations staff to quickly locate a particular asset, especially under fault conditions or if the asset has been moved during a prior rack or site reconfiguration.
Different systems offer different types of asset location information. For example, one system provides room level information regarding what room in the data center an asset is physically located in. In this system, the room is flooded with an IR signature that the tags can interpret and re-transmit over their RF channel to a reader located in the room. Hence, the reader can determine the coarse location (with respect to an IR transmitter placed at a known location). The coarse location information provided by this system, however, does not provide positioning and ordering information of the asset within the rack.
Indoor location techniques based on wireless signal characterization have been implemented in combination with active RFID (radio frequency identification) tags to form location aware asset tags. One approach relies on performing RF signal strength (RSSI) measurements that act as a proxy for propagation path distance. Although suitable for free-space (line of sight) deployments, their use within aggressive indoor environments such as the data center remains challenging (multiple RF pathways, sources of RF noise, metallic surfaces, conditions conductive to the formation of standing wave). Further these RF signal strength implementations typically do not provide sub-meter range accuracies for facilitating determination of asset location in a rack. Carrier-less or ultra-wide RF systems have also been demonstrated and offer improved (sub-meter) resolution accuracies but, as a general rule, these are also susceptible to the same environmental RF issues identified above.
Conventional RFID asset tracking systems attach RFID tags to assets within the rack. The RFID tags communicate with a reader or base station via short range RF signaling, as long as the tags are all within operating range of the reader. However, although the reader is made aware of the assets within the rack, the reader does not know the relative ordering or absolute position of the assets within the rack.